THURSDAY, Sept. 13 (HealthDay News) -- New research suggests that Hispanic children with developmental delays often are undiagnosed, and both Hispanic and non-Hispanic kids who are diagnosed with developmental delays often actually have autism.

"Our study raises concerns about access to accurate, culturally relevant information regarding developmental milestones and the importance of early detection and treatment," Virginia Chaidez, the study's lead author and a postdoctoral researcher in the public health sciences department at the University of California, Davis, said in a university news release.

"Autism and developmental delay tend to go undiagnosed when parents are not aware of the signs to look for, and the conditions are often misdiagnosed when parents don't have access to adequate developmental surveillance and screening," she added.

The study, published in a recent issue of the journal Autism, is one of the largest of its kind to date, according to the release.

Developmental delay and autism aren't the same thing. Children with developmental delay don't move as quickly as expected through physical or mental development, while kids with autism have trouble interacting with others, the study authors pointed out in the release.

For the new study, the researchers examined the findings of a study of more than 1,000 children in California, aged 2 to 5 years. Some developed normally, while others had developmental delays or autism.

Of the Hispanic kids in the study, 6.3 percent had signs of developmental delay compared with 2.4 percent of non-Hispanics. And of the children overall, about 19 percent who had been diagnosed with developmental delay actually appeared to have autism, the investigators found.

"Our results emphasize the importance of considering cultural and other family factors such as multiple language exposure that can affect development when interpreting clinical tests, even when they are conducted in the child's preferred language," study co-author Robin Hansen, chief of developmental-behavioral pediatrics at UC Davis, said in the news release.

"That so many children are slipping through the cracks is disheartening," Hansen added. "The differences between developmental disabilities can be subtle but important, and involve distinct treatment pathways. We need to make sure that all children are getting routine developmental screening, early diagnosis and intervention so they can achieve their fullest potential."